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Use of catalytically coated short contact time (SCT) design approaches for application in mass transfer controlled reactors such as Auto Thermal Reformers (ATR's) is an area of much recent interest. Precision Combustion, Inc. (PCI) has developed an efficient and compact ATR using ultra-short channel length, high cell density SCT substrates (Microlith®). PCI has also extended this Microlith technology to other fuel processor reactors that operate at lower temperatures and are not mass transfer limited. Namely, reactors for the Water Gas Shift (WGS) and Preferential Oxidation (PROX) of CO have been developed. Due to the higher surface area per unit volume of the Microlith substrate compared to conventional monoliths, size advantages have been observed for these reactions, which are more kinetically controlled.

The performance of the fast lightoff, ultra-short metal monolith (SMM) catalyst technology was evaluated in a laboratory rig capable of simulating automotive exhaust streams. Tests focused primarily on determining the lightoff behavior of the fresh and engine aged catalyst over a wide range of air to fuel ratios (A/F). Experimental results are compared with estimates of mass transfer controlled operation for the geometry of the catalyst substrate. The effects of different space velocities, cycling between rich and lean gas streams, and addition of SO2 are also investigated. Additionally, the effect of thermal aging on the catalyst/substrate interface is discussed.

Reducing light-off time by using low thermal mass preconverters and increasing catalyst conversion efficiencies is one way of reducing cold start emissions and attaining mandated emission standards. Additionally, it is desirable to attain these features in a small, flexible package helping to overcome close coupling design constraints. Such a preconverter with an atypical Microlith™ metal catalyst substrate geometry and capable of withstanding high operating temperatures using a proprietary catalyst coating technique was tested with a conventional downstream ceramic main brick. This paper explains the physical characteristics and the flow dynamics of this substrate. Development and testing of prototypes were done on a bench scale apparatus and in automobiles. Bench scale catalyst performance and automotive FTP data before and after aging are presented. Automotive tests were done with and without secondary air and with calibrated Air/Fuel bias.

A system using catalytically ignited recirculated exhaust gas (EGR) has been shown to be capable of starting a heavy-duty diesel engine at temperatures as low as 31.6°C (-25°F) within one minute cranking following US Army Cold Start procedure 2-2-650. A Cummins 6-cylinder C8.3 automotive diesel engine was provided with an EGR pipe fitted with a catalytic ignitor/burner. During starting, the catalyst was kept above the activation temperature by a low power electric power supply. With this system, the unburned fuel in the EGR gas was rapidly ignited by and partially oxidized within the catalytic ignitor/burner, and then mixed with the fresh air before being inducted into the cylinders. The elevated inlet charge temperatures increased the compression temperature, thus promoting autoignition and therefore engine starting. Comparisons were made between starting attempts with and without using catalytically ignited EGR.

This paper discusses a new type of compact hydrogen generator suitable for integration into fuel cell power systems. Such generators not only provide a source of ultra-pure hydrogen especially suited for fuel cell use but at the same time could, in principle, achieve thermal efficiencies approaching 100% for the conversion of hydrocarbons into hydrogen. As a result it should now be possible to build small fuel cell power packages, even as small as 500 watts, which can operate at thermal efficiencies greater than those of large power plants.